1. Field of the Invention
The present invention relates to a wheeled shopping bag device, and more particularly, to a collapsible, lightweight, yet strong, low cost, recyclable and disposable-wheeled shopping bag device that is environmentally compatible with characteristics that readily allow for its compact stacking, easy deployment, quick opening, stability, and structural strength.
2. Description of the Related Art
Several designs for wheeled shopping bags have been designed in the past. None of them, however, includes the conveniences claimed herein. The present invention utilizes eco-friendly materials with greater resistance and capacity than conventional bags, achieving low cost and weight characteristics, while maintaining sufficient strength and being collapsible for compact stacking and storage as well as being easily deployed by a user.
Applicant believes that the closest related reference corresponds to U.S. Pat. No. 3,197,225 issued to Powell for a Collapsible Shopping Bag hereinafter “Powell Bag”. However, it differs from the present invention because, it relies on the use of hinges and supports made of sheet metal, fabric, or a combination thereof with the intent of being reused and does not rest on its roller system assembly when at rest due to the obtuse angle of attachment of the wheels. The present invention, on the other hand, is made of a disposable, lightweight material, yet with some rigidity, that sits on its roller system when at rest, aided by folds causing it to stand in a substantially upright position. Furthermore, the patented bag does not claim or demonstrate any stacking characteristics if collapsed. Nor does it disclose crossed-members for its base assembly to reduce weight and costs as claimed herein.
One of the disadvantages of the current designs for wheeled bags is that they rely on a multiplicity of parts, such as hinges, fasteners, and reinforcing members, to achieve stability and collapsibility. These parts result in high material and manufacturing cost. These designs must accommodate long term personal reuse, and thus focus on collapsing to the smallest possible dimensions to permit a person to carry them. Still another shortcoming of the current designs is that they are unsuitable for stacking due, among other factors, to lateral instability, protrusions of rigid supports, bulk, and lack of flat surfaces.
The present invention provides a low weight and volumetrically efficient solution for collapsible bags that permit its rapid folding and deployment by using a combination of folds and slots to permit the air to vent in and out of the bag. Trapped air prevents the rapid collapse of bags, especially if the bag's opening is closed. In folding a bag, the opening at the distal end of the bag is typically closed and then folded along a predetermined first folding line, then a second one, until different layers of the flattened bag are stacked over each other. In doing this, air is trapped inside the bag providing some resistance to the folding operation. By providing slots along the vertical walls of the bag, preferably along its diagonal folds, the air inside is allowed to exit. This facilitates the folding of the bag. The reverse operation is also helped. As a user unfolds the bag, air enters through the bag's opening as well as through the slots.
The base or bottom assembly in the present invention includes a pair of coaxially disposed wheels mounted to its underside, opposite to each other at the end of a shaft. The other end includes a spacer leg assembly, opposite to the shaft supporting the coaxially disposed wheels. The dimensions of the spacer leg assembly cooperate with those of the wheels to permit the bag assembly to be at an upright position when at rest. In one of the embodiments, the bottom assembly is implemented using moldable material technology. Minimization of the material used is achieved with two crossed, elongated, and rigid members using molding technology. In one of the embodiments, the crossed members include through openings for permitting the glue to go through and achieve better engagement of the base assembly with the bottom of the bag member. Reinforcement angular members further strengthen the attachment to bushing members that journal the shaft supporting the wheels. Another way of attaching the bottom of the bag members to the base is through the use of ultrasound welding. For this, the paper used for the bag member is covered with a thin film of plastic material that is welded with the plastic material used for the cross members. None of these features are disclosed in the prior art.
The present invention also solves the prior art problems by using a bottom or base assembly with simple parts and paper bags that can be glued and do not require hinges or similar hardware. Strength of the wheeled base is enhanced through the use of reinforced cross-members with a substantially flat upperside. As a result of the design, multiple units may be stacked stably in their collapsed states. The folding characteristics of paper bags achieve collapsibility when integral hinges or folds are created along cooperative locations. The folds are positioned so that the folded portions of the bag member leave a clearance for the spacer leg members to fit in the collapsed disposition.
Other documents describing the closest subject matter provide for a number of more or less complicated features that fail to solve the problem in an efficient and economical way. None of these patents suggest the novel features of the present invention.